fn foo() -> ! {
    panic!("This call never returns.")
}

fn some_fn() {
    ()
}


fn main() {
    // panic!("this call never returns.");
    // println!("You will never see this line!");
    // let a: () = some_fn();
    // println!("Hello, world!");
    fn sum_odd_numbers(up_to: u32) -> u32 {
        let mut acc = 0;
        for i in 0..up_to {
            let addition: u32 = match i % 2 == 1 { true => i, false => continue, };
            acc += addition;
        }
        acc
    }
    println!("Sum of odd numbers up to 9 (excluding): {}", sum_odd_numbers(10));
}
